Early Miocene (3)
Discoaster (12)
Sphenolithus (20)
Helicosphaera (14)
Neochiastozygus Perch-Nielsen, 1971
Description: Muroliths with well-developed V- and R-units and diagonal or asymmetric cross in central-area.
Remarks:
Type species:
Predominantly Paleocene group.
Paleogene: Neochiastozygus